British Museumin London, comprehensive national museum with particularly outstanding holdings in archaeology and ethnography. It is located in the Bloomsbury district of the borough of Camden.

Established by act of Parliament in 1753, the museum was originally based on three collections: those of Sir Hans Sloane; Robert Harley, 1st earl of Oxford; and Sir Robert Cotton. The collections (which also included a significant number of manuscripts and other library materials) were housed in Montagu House, Great Russell Street, and were opened to the public in 1759. The museum’s present building, designed in the Neoclassical style by Sir Robert Smirke, was built on the site of Montagu House in the period 1823–52 and has been the subject of several subsequent additions and alterations. Its famous round Reading Room was built in the 1850s; beneath its copper dome laboured such scholars as Karl Marx, Virginia Woolf, Peter Kropotkin, and Thomas Carlyle. In 1881 the original natural history collections were transferred to a new building in South Kensington to form the Natural History Museum, and in 1973 the British Museum’s library was joined with a number of other holdings by act of Parliament to create the British Library. About half of the national library’s holdings were kept at the museum until a new library building was opened in 1997. Plans were then announced for the refurbishment of In the late 1990s the Reading Room , which would house was closed for renovations, and among its improvements was a new reference collection including that includes computer systems. Construction of the glass-enclosed Great Court, In addition, the Great Court (designed by Sir Norman Foster), a glass-roofed structure surrounding the Reading Room, began in March 1998was built. The Great Court and the refurbished Reading Room opened to the public in 2000.

Among the British Museum’s most famous holdings are the Elgin Marbles, consisting mainly of architectural details from the Parthenon at Athens; other Greek sculptures from the Mausoleum of Halicarnassus and from the Temple of Artemis at Ephesus; the Rosetta Stone, which provided the key to reading ancient Egyptian hieroglyphs; the Black Obelisk and other Assyrian relics from the palace and temples at Calah (modern Nimrūd) and Nineveh; exquisite gold, silver, and shell work from the ancient Mesopotamian city of Ur; the so-called Portland Vase, a 1st-century-AD cameo glass vessel found near Rome; treasure from the 7th-century-AD ship burial found at Sutton Hoo, Suffolk; and Chinese ceramics from the Ming and other dynasties.

See also British Museum from Encyclopædia Britannica’s 2nd edition (1777–84), which includes a partial list of the institute’s holdings in the late 18th century.